Stuttgart court rules activated water no better than tap water in Tennant vs Kärcher case

4th of July 2013

In the long running legal dispute between cleaning machine manufacturers Tennant and Kärcher, the Stuttgart Regional Court - which is local to the Kärcher HQ - has ruled that advertising claims by Tennant regarding its ec-H2O technology are misleading.

The basis of the lawsuits brought in Germany, Belgium and the UK is a number of advertising claims made by Tennant, particularly the assertion that ordinary tap water can in scrubber dryers be converted into ‘active water' that then has the same effect as a powerful cleaning agent, therefore dispensing with the use of chemical cleaning agents to clean floors.

The ruling was pronounced against the German subsidiary of the US American Tennant Company, Tennant GmbH & Co KG in Kirchheim/Teck. Tennant will now be required to cover the costs of the legal dispute, although it may still appeal against the ruling.

After carrying out its own practical tests Kärcher commissioned an expert opinion from the scientific institute MicroMol in Karlsruhe. All the investigations came to the same conclusion - as did the impartial expert witness Thomas Hofmann (Zurich University of Applied Sciences) appointed by the Regional Court: Tennant's advertising claims relating to the process technology of 'activated' water are scientifically untenable.

The fact some users still believe they can detect a certain cleaning effect is achieved despite changing over to tenside-free cleaning can be simply explained, in the experience of expert witness Thomas Hofmann: "Even after changing over to cleaning without tensides, as a result of 'frequent poorly metered (excessive) application' of cleaning agents during previous cleaning processes, tensides still continue to be given off from the porous floor structure for around six months.

"To start with, this gradual degradation process frequently results in an improved appearance. However, once the material deposits are finally used up, the dirt build-up begins to increase again."

The following statements have been assessed as misleading:

• ec-H2O technology activates water to perform like a powerful detergent

• ec-H2O makes its own powerful cleaner

• ec-H2O cuts costs because there is no need to buy a universal detergent for scrubber dryers

• ec-H2O is a 'proven technology'

In its ruling the regional court established indisputably that dirt caused by substances containing mineral oil could not be removed using scrubber dryers equipped with ec-H2O technology.

In its written statement of reasons for the ruling, the Court accepted the conclusion of the evidence heard: "[...], that the cleaning effect of water treated using ec-H20 technology is no better than that of pure tap water, and in particular is in no way comparable to that of a strong or powerful cleaning agent or all-purpose cleaning agent."

"We very much welcome the decision of the Court to abide by the scientific argument put forward by the court-appointed expert witness," commented Markus Asch, vice chairman of Kärcher on the judgment. "With this ruling, the industry has practised the best form of self-regulation in the interests of consumer protection."

Tennant, from its headquarters in the US, has said it is likely to appeal the court decision as it was made based on "incomplete and inaccurate information".

"The two laboratory bench tests performed by the court appointed advisor had no or too little correlation to cleaning with a scrubber dryer using Tennant’s ec-H2O chemical-free technology,” said Chris Killingstad, president and ceo of Tennant Company.

Tennant Company continues to stand behind its advertisements of the ec-H2O technology based on extensive internal and external tests and the experiences of customers who have years of experience cleaning with ec-H2O since it was launched in 2008, according to Killingstad.

Tennant maintains he two laboratory bench tests performed by the court appointed advisor were seriously flawed. The first test had no applicability to Tennant’s ec-H2O chemical-free technology as the test is typically used to measure properties in traditional chemical cleaners. The second bench test - even if properly performed - has little correlation to cleaning with a scrubber dryer says Tennant, regardless of the cleaning solution, including ec-H2O.

In addition, the soil sample – comprised of 90 per cent fat and 10 per cent insoluble pigment - could not be cleaned by a scrubber dryer even if using a concentrated degreasing agent. “A laboratory test or bench test in isolation of real-world conditions cannot in and of itself accurately reflect the variability present in a customer’s real-world environment,” Killingstad said.